Here is the full list of all 23 Iron Danger achievements.
You successfully completed Iron Danger. Congratulations!
You found the fifth Shard. Your enemies tremble before you.
You put the Tyrannogrouse out of its misery.
Eat roosterfish roasted over campfire.
You found the fourth Shard, and it eases your pain.
Kill the alpha Roosterfish in the temple under Rimfeden.
Die 100 times.
You found the third Shard, and it makes you shiver.
Defeat 100 enemies.
You found the second Shard and feel the nature's call.
Kill 30 keyus.
You found the fabled Healer of Brumehead.
You found the first Shard poking through your chest.
Collect 30 mushrooms.
Collect 20 berries.
You healed the wounded Tyrannogrouse.
Use Earthquake while boosted by fire.
Blow yourself up by shooting explosive arrow while on fire.
Take a troll into the Northlander camp.
Find and read the recipe in Kalevala.
Grow stealth grass 20 times.
Hunt down and slay all of the trolls in Bleakshore.
Destroy all three gates leading into the Northlander camp.